A cold front associated with
a strengthening upper-level disturbance supported the development of severe
thunderstorms with in some cases exceptionally large hail.The front was split, with one axis of
convection in western and northern NY to parts of Vermont.The other
axis of convection extended from southern NY into southern New England.Vertical
cross sections of some of the thunderstorms revealed reflectivities aloft >
70 dBZ, which is very rare.

Compare GFS and NAM theta-e forecasts at the surface
and 925 hPa with MSAS observed surface theta-e, surface dew points and the wind
barbs identify the actual cold front in the Great Lakes area.There was a definite prefrontal boundary in
southern NY and New England, with the
surface front further north and west.Both the GFS and NAM showed the
larger CAPE values in southern areas.

Loop of the High Resolution WRF predicted composite
reflectivity, which made quite a good prediction.

Radar Loops

KENX Loop from 1800-1900 UTC of reflectivity and
Severe Thunderstorm Warning Polygons – Previous polygons were not available due
to data archive issues.NWS Binghamton and NWS Buffalo had warnings
in effect for the storms in central and western NY, even though they are not
displayed in this loop.

KENX Loop from
1900-2000 UTC of reflectivity and Severe Thunderstorm Warning Polygons -
Previous polygons were not available due to data archive issues.NWS Binghamton and NWS Buffalo had
warnings in effect for the storms in central and western NY, even though they
are not displayed in this loop.

KENX Loop from 2100-2200 UTC of reflectivity and
Severe Thunderstorm Warning Polygons - Previous polygons were not available due
to data archive issues.NWS Upton and
NWS Taunton had warnings in effect for the storms in NY, NJ and New England,
even though some are not displayed in this loop.

KENX Loop from 0030-0130 UTC 6/27 of reflectivity and
Severe Thunderstorm Warning Polygons - Previous polygons were not available due
to data archive issues.NWS Upton and
NWS Taunton had warnings in effect for the storms in NY, NJ and New England,
even though some are not displayed in this loop.

Four Dimensional Storm
Investigator Images of specific severe thunderstorms as viewed from the KENX
radar